initial commit with my changes

examples/hello.rs

@@ -0,0 +1,20 @@
+//! Prints "Hello, world!" on the host console using semihosting
+
+#![no_main]
+#![no_std]
+
+use panic_halt as _;
+
+use cortex_m_rt::entry;
+use cortex_m_semihosting::{debug, hprintln};
+
+#[entry]
+fn main() -> ! {
+    hprintln!("Hello, world!").unwrap();
+
+    // exit QEMU
+    // NOTE do not run this on hardware; it can corrupt OpenOCD state
+    // debug::exit(debug::EXIT_SUCCESS);
+
+    loop {}
+}